Somatostatin receptor scintigraphy in the management of cerebral malignant ectomesenchymoma: a case report

A 10-year-old girl presented with a cerebral malignant ectomesenchymoma (MEM), a very unusual tumour with undifferentiated mesenchymal as well as ectodermal elements. Somatostatin receptor scintigraphy (SRS) was performed during the diagnostic workup. The recurrent residual tumour mass was exactly visualized with SRS, and was negative after successful treatment of the patient. The potential application of SRS in initial staging, follow-up and therapy planning in MEM is discussed. This is the first application of SRS in MEM. Received: 14 May 1999 Accepted: 8 May 2000     

Über die Steigerung des Nutzeffektes der Plantationsverfahren mit Hilfe geeigneter Fixierungsmaßnahmen

Zusammenfassung Bericht über den Stand der „Odontoplastik“, d. h. die Replantation, Transplantation und Implantation in der Zahnheilkunde. Ergebnisse der Plantationsverfahren unter Mitteilung von Krankengeschichten.     

The approximate planimetric method: a simple,rapid and reliable method for estimation of lesion size in acute ischemic stroke

Magnetic resonance imaging is increasingly used in stroke trials for early diagnosis and follow-up of lesion size. Since volumetric measurement remains a laborious and time-consuming task, a rapid and reliable method for the assessment of lesion size has been developed and validated in diffusion weighted imaging (DWI) and fluid attenuated inversion recovery (FLAIR) sequences. These were serially obtained in 40 patients less than 8 h after the onset of symptoms of a middle cerebral artery territory stroke (day 1), as well as on days 3 and 18. For each of 16 (DWI) or 20 (FLAIR) transverse sections obtained on each occasion, lesion size was estimated as a percentage of the total hemisphere. Percentage values from all sections were summed up and expressed as arbitrary units. Results obtained using this approximate planimetric method (APM) were compared with those from a standard volumetric approach. Lesion volumes as determined by both methods were highly correlated (DWI: r = 0.966, FLAIR: r = 0.979, p < 0.001). To conclude, the APM is simple, rapid and reliable for the estimation of lesion size in acute ischemic stroke. It can be recommended for broader application in clinical trials.     

Medical workstations for applied imaging and graphics research

We present a medical workstation for the efficient implementation of research ideas related to image processing and computer graphics. Based on standard hardware platforms the software system encompasses two major components: A turnkey application system provides a functionality kernel for a broad community of clinical users working with digital imaging devices, including methods of noise suppression, interactive and automatic segmentation, 3D surface reconstruction and multi-modal registration. A development toolbox allows new algorithms and applications to be efficiently implemented and consistently integrated with the common framework of the turnkey system. The platform is based on an elaborate object class structure describing objects for image processing, computer graphics, study handling and user interface control. Thus expertise of computer scientists familiar with this application domain is brought into the hospital and can be readily used by clinical researchers.     

Bestimmung von Schuhinnenmaßen—Zerstörungsfreie Werkstoffprüfung mittels Computertomographie

Zusammenfassung Insbesondere beim Kinderschuh kommt der optimalen Anpassung hinsichtlich Erkrankungen des Stütz- und Bewegungsapparates im Erwachsenenleben große Bedeutung zu.Es wird ein Verfahren mittels Computertomographie zur zerstörungsfreien Prüfung beschrieben, bei dem der zu prüfende Schuh lückenlos mittels Computertomographie (CT) untersucht wird. Mit Hilfe von Nachverarbeitungsprogrammen (MATLAB) und 3DSoftware (AMIRA) werden die Daten analysiert und die für den Konstrukteur maßgeblichen Maße automatisch bestimmt. Durch Vergleich des für die Herstellung des Leistens verwendeten CAD-Datensatzes mit dem computertomographisch gewonnenen Binnenraum eines darauf aufgebauten Schuhmodells können Abweichungen sichtbar gemacht werden. Messungen mit dem beschriebenen Verfahren zeigten, dass die Innenräume von Schuhen zerstörungsfrei sichtbar gemacht werden können. Beliebige Punkte des Schuhinnenraums konnten bestimmt, Strecken vermessen und Volumen berechnet werden. Es konnten Größen bestimmt werden, die bei der Schuhkonstruktion eine wichtige Rolle spielen und dementsprechend sich auch im fertigen Schuh wieder finden sollten (Brandsohle). Es war aber auch möglich Maße zu ermitteln, die fußrelevanter sind wie z.B. die tatsächliche Länge und Breite des Schuhinnenraums. Hierfür wurde der Parameter „+1 cm“ eingeführt. Dieser beinhaltet z. B. die Länge und Breite des Schuhinnenraums in 1 cm Höhe über der Brandsohle und berücksichtigt die Lage der tatsächlichen Länge und Breite des Fußes.     

Integrated 3D display of brain anatomy and intracranial vasculature in MR imaging

In many clinical situations neuroradiologists and neurosurgeons are keenly interested in images displaying both brain structures and intracranial vessels in an integrative manner. In this paper an approach to three-dimensional visualization of brain and vascular structures from magnetic resonance (MR) volume data is reported. It has been designed with the aim of providing a robust and reliable image processing tool for routine clinical applications. The method has been made possible by recent developments in MR image acquisition, especially MR angiography and rapid gradient-echo sequences (Turbo-fast low angle shot). On the basis of the ray-tracing principle, integration of brain and vessel anatomy into a single 3D image is achieved. Image data are acquired with flow-compensated gradient-echo pulse sequences. Even slow flow in venous structures may be demonstrated using a two-dimensional sequential-slice scanning method. Finally, if incorporated into an interactive image processing system, this technique may be used as a planning tool allowing a surgical "rehearsal" prior to actual operative exposure and resection of a lesion.     

Use of MR angiography for stereotactic planning.

With the introduction of MR angiography (MRA) into clinical routine MR protocols, it has become possible now to image flowing as well as stationary tissue with excellent contrast using a single modality. This has opened up new perspectives for planning stereotactic approaches, which are characterized by high risks for damaging intracerebral vessels or vital brain structures. In this article we present an MRA based planning method for the treatment of arteriovenous malformations by stereotactic radiosurgery. It includes flow compensated gradient echo pulse sequences for the acquisition of angiographic MR datasets, a stereotactic MR marker system, an algorithm for the correction of geometric distortion of MR image data, and a three-dimensional workstation system for the creation and evaluation of treatment plans. The latter is based on the concept of simultaneously displaying both MR slice and angiographic projection images. This allows the evaluation of intracerebral vasculature together with brain anatomy. The MRA guided planning approach was tested and compared to a conventional X-ray angiographic technique in a clinical study. Our satisfactory results suggest that MRA is a technique that can be used advantageously for stereotactic planning.     

MRA-guided stereotactic radiation treatment planning for cerebral angiomas.

Stereotactic neurosurgical interventions are characterized by a high risk of rupturing intracranial vessels or damaging vital brain structures. By MRI and MRA, the anatomic information necessary for stereotactic treatment planning may be assessed with a single modality as a high-resolution digital image volume. The adequacy of MR as a modality for stereotactic guidance is demonstrated by the example of the radiosurgical treatment of cerebral angiomas. An optimized acquisition protocol, a stereotactic apparatus, a distortion correction and minimization method, and a 3D treatment planning workstation are elements of a proposed preoperative approach which in a clinical study met with good acceptance.